Ltjbricating-strip for leaf-springs



T. S. HAMILTON.

LumcMlNG STRIP FoR LEAF SPRINGS.

APPLICATION FILED AUGJB. |919. f 1,323,856. Patented Dee. 2,1919.

' UNITED sTATEs PATENT -oEETcE THOMAS S'. HAMILTON, OF PORTLAND, OREGON, ASSIGNOB 0F ONE-HALF T0 WILLIAM E. MERRILL, 0F KANSAS CITY, MISSOURI.

'LUEnIcATxNGsTEIP Fon. LEAF-srnmos.

A Specification et Letters .Patent Patented Dec. 2, 1919.

'To all lwhom it may concern.'

Be it 'known that I, THOMAS S. Hairmron, a citizen of the United States, resldlng at Portland, in the county of Multnomah and State of Oregon, have invented certain new and useful Im rovements inLubricatmg- Strips for Lea -Springs, of which the following is a specification.

This invention relates to new and useful improvements in a lubricating strip for leaf springs and method of producing the same.

Heretofore lubrication of leaf springs has generally been accomplished by separating the leaves of the spring and placing oil between the same with an oil can or the like. An eil'ort has been made to produce a lubricating strip which may be laced between the leaves of the spring a Ording a continuous oil supply therefor but all of these strips with Whlch I am familiar have been formed of compressible material soaked with a lubricating agent. The feature of compressibilit is an undesirable one in that the compressi ilit -of the stri allows play in the sprin andl causes it to ecome loose and break. Elso when this carrier strip has been subjected to continuous action for some time, it becomes so compressed that it slips out between the leaves of the spring.

The use of a ready flowing lubricant in such a carrier is hi hly undesirable in that the action of the spring squeezes the oil from the carrier and it collects upon the edges of the spring and dirt and dust from the road adhere thereto. Then in cleaning the spring to remove the rease it is necessary to use gasolene and this use of gasolene has a tendency to destroy the lubricating properties of the lubricant in the strip. Graphite has been laced upon the face of these compressi le strips but inthe presence of oil, graphite has a tendenc to becomea gummy mass, which due to its hesive properties has a tendency to retard rather than promote free movement of the spring.

Also in the majority of cases where such a strip is used in order to hold the strip in place it is necessary that it must be continuous throughout the leaf of the spring and the spring therefore must be taken apart' to insert the strip.

v ese objections I have overcome by forming a very thin strip provided upon one side wlth an adhesive to secure it to the spring. Upon the other side of the strip is placed a composition extremely hard in texture yet having a hi h coefficient of lubrication.

`Other ob}ects and advanta eS of the invention will be apparent during the course of the following description.

In the accompanying drawings formin a part of this specification, and in which like numerals are employed to designate like parts throughout the same:

Figure 1 is a side elevation of a spring embodying my invention;

Fig. 2 is an enlarged transverse section therethrpugh Fig. 3 is an enlarged lubricating strip; Fig. 4 is a sectional view illustrating the construction used where the strips are applied to both the upper and under surfaces of the spring, and,

Fi 5 is a longitudinal section of the doub ed strip.

Referring now more particularly to the drawings, the numeral 10 indicates the leaves of a spring and the numeral 11 the lubricatin strip placed intermediate these leaves.

he strlp 11 is formed by placing upon one face of a layer of fabric, such as top cloth, such as is ordinarily used for automobile tops, oil-cloth, paper, canvas, hair cloth, Wire gauze, or the like, a paste comprising the following ingredients:

A binder, viz.-shellac, silicate of soda,

varnish glue or the like 1 qt. A dry-lubricant, viz.ne powdered graphite, mica or soapstone 1 lb. Powdered alum 1 oz.

The fabric 1n a smooth even layer and then upon the surface of the paste I sprinkle onequarter lb. heavy `Hake graphite. The strip is then put under pressure in a warm press for approximately twenty minutes and then ed in an oven fora period of about four hours. It is to be understood that I do not limit myself to any specific heat or time for baking the composition, as in some cases it may be desirable to form a. harder product than in others and the hardness of the product depends entirely upon the length of time it is baked.

This fabric is then cut into stri s of the slze desired for the s ring to whic it is to be applled and an a heslve applied to the opposite side thereof.

section through the paste is applied to the surface of the This process forms a very hard thin strip and the graphite applied to the face of the composition tends to fill the minor roughness of the leaf.

The strip is then placed between the leaves of the spring b prying each apart and placing the strip etween the same, the strip terminating short of the center of the spring. The ummed side of the strip adheres to the ace of'vthe leaf a ainst which it is placed and prevents shi ting of the strip, while the side bearing the composition rovides a smooth dry lubricating surface or the shifting of the spring. In some cases it may be desirable to place two stri s between each leaf with the faces bearing tlie lubricant together so that the friction lies between the surfaces of the strips and not between the strip and the spring.

Having thus described my invention, I claim:

1. A lubricating strip for leaf springs comprisin a strip of fabric provided upon one side tereof with an adhesive and upon the other side with a layer of lubricant.

2. A lubricating strip for leaf springs comprising a strip of fabric provided upon one side thereof with an adhesive and upon the other side with a layer of dry lubricant.

3. A lubricating str1 for leaf springs vcomprising a strip of fa ric provided upon one side thereof with an adhesive and upon the other side with a layer of hard lubricant.

4. A lubricating strip for leaf springs comprisin a strip of fabric provided upon one side t eieof with an adhesive and upon the other side with a layer of lubricant comprising shellac, graphite and alum.

5. A lubricating stri for leaf springs comprising a strip of fa ric provided upon one side thereof with an adhesive and upon the other side with a layer of hard lubricant comprising shellac, a d lubricant and alum and a filler applied to t layer of lubricant.

6. A lubricating strip for leaf springs e outer lface of'said comprisin a strip of fabric provided upon one side t ereof with an adhesive and upon the other side with a layer of hard lubricant comprising a dry lubricant and a watery binder ada ted to harden under the action of heat an ressure.

7. A lubricating strip for leaf s rings comprisin a strip of fabric provid upon one side t ereof with an adhesive and upon the other side with a layer of hard lubricant comprising gra hite and a watery binder adapted to har en under the action of heat and pressure and a filler applied to the outer face of said layer of lubricant.

8. The herein-described method of producing a lubricating strip for leaf springs consisting in su plying a strip of fabric, applying t0 one ace thereof a watery binder containing a dry lubricant, placing the strip under pressure and subsequently baking the strip.

9. The herein-described method of producing a lubricating strip for leaf springs consisting in supplying a strip of fabric, applying to one face thereof a paste formed by combining shellac, a dry lubricant and alumyplacing the strip under pressure, baking the strip and applying to the opposite face of the strip an adhesive.

10. The herein-described method of producing a lubricating strip for leaf s rings consisting in su plying a strip of ibloric` applying to one ace thereof a paste formed by combining a. watery binder-with 'a powdered dry lubricant and a smallpercentil e of alum, sprinkling upon the surface of tie paste Hake graphite, placing the strip under pressure, bakin the strip and applying to the opposite ace thereof an adhesive.

In testimony whereof I aliix my signature in presence of two witnesses.

THOMAS S. HAMLTON.

Witnesses z 4 JN0. WARREN, L. R. Zulema. 

